Many liquids contain suspended solids which must be removed before the liquid can be used for industrial and domestic purposes. Thus, water from rivers and lakes contains dissolved solids which must be precipitated and then removed before the water can be used. Water from such sources, and of other origins, often contains suspended solids which need to be separated out before the water can be used for municipal purposes. Water, however, is not the only liquid which must be treated to remove solids. Various petroleum-based liquids also require treatment to eliminate solids.
Wyness U.S. Pat. No. 4,146,471 discloses apparatus and methods of treating water containing solids to produce purified or clarified water. According to the patent disclosure, water containing suspended solids is caused to flow in an upward helical path in a suitable vessel. The solids are thereby induced to migrate or move radially inwardly thus forming a concentrated blanket of solids which is removed through a central downcomer. The water collects above the blanket, which functions as a filtering media. The water above the blanket then flows over a peripheral weir and travels to a conduit for delivery to a predetermined destination.
Although the system of the Wyness patent, supra, supplies a purified water, it still contains some suspended solids which could be beneficially removed if a suitable method and apparatus were available. What is accordingly needed is a system for lowering or reducing the suspended solids content in a helical or circular flowing stream of water just prior to its removal from the top of a water body in a vessel, such as when the water is discharged to an outlet or flows over a weir.